Ethanol-driven Room-temperature Synthesis of Potential Green-emitting Phosphors： a Case Study of Tb^3＋-doped CaHPO4

A novel green nanophosphor CaHPO4：Tb3＋ was synthesized via a room-temperatureco-precipitation route driven by ethanol solvent. X-ray powder diffraction （XRD）, scanningelectron microscopy （SEM） and photoluminescence spectroscopy （PL） techniques were utilizedto characterize the structure, morphology and fluorescence performance of the obtained powders.The results demonstrated that the prepared samples were well crystallized with triclinic phaseCaHPO4 structure and particle-like morphology. Photoluminescence measurements indicated thatCaHPOa：Tb3＋ had a strong absorption peak at 370 nm and exhibited characteristic emissions withseveral sharp peaks corresponding to the transitions 5D4-7FJ （jr = 6-3） of Tb3＋. Moreover, theluminescence optimum concentration for CaHPO4：Tb3＋ was determined to be 11 mol%, whichmight be a promising green-emitting ohosohor for display applications.

Room Temperature Synthesis of Vertically Aligned Amorphous Ultrathin NiCo-LDH Nanosheets Bifunctional Flexible Supercapacitor Electrodes

Developing a simple scalable method to fabricate electrodes with high capacity and wide voltage range is desired for the real use of electrochemical supercapacitors.Herein,we synthesized amorphous NiCo-LDH nanosheets vertically aligned on activated carbon cloth substrate,which was in situ transformed from Co-metal-organic framework materials nano-columns by a simple ion exchange process at room temperature.Due to the amorphous and vertically aligned ultrathin structure of NiCo-LDH,the NiCo-LDH/activated carbon cloth composites present high areal capacities of 3770 and 1480 mF cm^(-2)as cathode and anode at 2 mA cm^(-2),and 79.5%and 80%capacity have been preserved at 50 mA cm^(-2).In the meantime,they all showed excellent cycling performance with negligible change after>10000 cycles.By fabricating them into an asymmetric supercapacitor,the device achieves high energy densities(5.61 mWh cm^(-2)and 0.352 mW cm^(-3)).This work provides an innovative strategy for simplifying the design of supercapacitors as well as providing a new understanding of improving the rate capabilities/cycling stability of NiCo-LDH materials.

SYNTHESIS OF THERMAL RESPONSE FACTORS AND Z-TRANSFER FUNCTION COEFFICIENTS FOR CALCULATION OF ROOM TEMPERATURE VARIATION

A new method is presented for getting the general thermal response factors and z-transfer functioncoefficients of a room by synthesizing them from the thermal response factors of different parts of the thermalinsulation structure. How to use the general thermal response factors and z-transfer function coefficients toca1culate the indoor air temperature variation directly is also studied. It is shown through practical use that it iseasy to program with the methods presented in this paper and the calculated results are reliable.

Room temperature synthesis of single-crystal Te nanorods from Na_2TeO_4

Single-crystalline tellurium nanorods were synthesized through the reduction of Na2TeO4 by hydrazine monohydrate, in the absence of surfactants, in an aqueous ammonia solution at room temperature. X-ray diffraction （XRD）, transmission electron microscopy （TEM）, and selected area electron diffraction （SAED） were used to characterize the composition and morphology of the products. The concentration of the OH ion has a significant influence on the morphology of the products and is found to be responsible for tailoring the crystal growth dynamically： the concentration of Te blocking in the solution is reduced via increasing the concentration of the OH^- ion, and subsequently the nucleation rate of Te is suppressed and Te nanorods gradually grow because of the inherently anisotropic structure of Te. New generation tellurium atoms add to the surface of the particles during the long period of reaction.

Clean synthesis of calix[4]crown-5-sulfonyl cyclothiourea derivatives at room temperature in aqueous solution

Calix[4]-crown-5-sulfonyl cyclothiourea derivatives 6 and 7 were synthesized from calix[4]-crown-5-monosulfonylethylenediamine derivatives 4 and 5 and carbon disulfide through nucleophilic addition and subsequent cyclization of intramolecule at room temperature in aqueous solution. The advantages of the novel protocol are the mild reaction condition, free organic solvent, simple final treatment, easy isolation of products and excellent yields.

Ultrasonic-Assisted Synthesis of Monodisperse Ag Nanoparticles and Their Applications in Surface Enhanced Raman Scattering and Fluorescence Enhancement

Monodisperse Ag nanoparticles with diameters of about 3.4 nm were synthesized by a facile ultrasonic synthetic route at room temperature with the reduction of borane-tert-butylamine in the presence of oleylamine （OAm） and oleic acid （OA）. The reaction parameters of time, the molar ratios of OAm to OA were studied, and it was found that these parameters played important roles in the morphology and size of the products. Meanwhile, surface enhanced Raman spectrum （SERS） property suggested the Ag nanoparticles exhibited high SERS effect on the model molecule Rhodamine 6G. And also, two-photon fluorescence images showed that the silver nanoparticles had high performances in fluorescence enhancement.

A New Dinuclear Zinc Polymer Based on 3-Methoxy-2-hydroxybenzaldehyde:Synthesis,Structure,Spectral Characterization and Hirshfeld Surface Analysis

A highly efficient fluorescence material dinuclear zinc polymer [Zn2（mhbd）2（dca）2]n （1, Hmhbd is 3-methoxy-2-hydroxybenzaldehyde, dca is N（CN）2？） has been synthesized under room temperature and structurally characterized by elemental analysis, IR, and single-crystal X-ray diffraction. The structure belongs to the triclinic system, space group P with a = 8.475（1）, b = 9.595（1）, c = 15.001（1） A, α = 86.84（1）, β = 81.10（1）, γ = 68.78（1）°, Mr = 565.15, V = 1123.5（1） ？3, Dc = 1.671 g？cm–3, F（000） = 568, μ = 2.185 mm–1, R = 0.0451, and wR = 0.1297. 1 is a dinuclear zinc complex which further constructs a 1D chain through double μ1,5-dca bridge. Luminescent property and Hirshfeld surface analysis of 1 have been studied. The result indicates that the fluorescence intensity of complex 1 is forty-one times the fluorescence intensity of Hmhbd ligand.

A Novel Method for the Synthesis of Mesoporous Molecular Sieve MCM-41

Using glycerol, glycol and water as solvent, cetyltrimethylammonium bromide (CTAB) as template, tetraethyl orthosilicate (TEOS) as silica source, ethylenediamine (EDA) as base source, mesoporous molecular sieve MCM-41 has been synthesized at room temperature, characterized by X-ray power diffraction and N2 adsorption. Compared with the samples synthesized by glycol and water, the samples synthesized by glycerol have larger pore diameter and high surface areas. Thus glycerol is an efficient solvent for preparing larger pore mesoporous MCM-41.

The Crystallization Behavior and Stability of Chromite Synthesized in Chromium-Containing Wastewater at Room Temperature

The ferrite process can not only purify wastewater containing heavy metal ions but also recycle valuable metals from wastewater. Therefore, it is considered a promising technology to treat chromiumcontaining wastewater. However, the process has not been extensively applied in industry due to its high synthesis temperature. In this paper, the feasibility of chromite synthesis at room temperature was comprehensively studied. The effects of critical factors on the effluent quality and the crystallization behavior and stability of the synthetic products were investigated. Results showed that the removal ratio of chromium from wastewater was over 99.0%, and the chromium concentration in the supernatant reached the sewage discharge standard after undergoing the ferrite process at room temperature. Increases in the aeration rate, stirring rate, and reaction time were favorable for the formation of stable chromite. The particles obtained by the ferrite process at room temperature were characterized by a compact structure, and the maximum size of the particles reached 52 μm. Chromium gradually entered the spinel crystal structure during the synthesis process, and the molecular formula of the synthetic chromite might be Fe3-xCrxO4, in which x was approximately 0.30. The path of the microscopic reaction was proposed to illuminate the synthesis mechanism of chromite under room temperature conditions. The present study has laid the foundation for the industrial application of the ferrite process in the purification and utilization of chromium-containing wastewater.

Rapid room-temperature synthesis of a porphyrinic MOF for encapsulating metal nanoparticles

While metal nanoparticles(NPs)have shown great promising applications as heterogeneous catalysts,their agglomeration caused by thermodynamic instability is detrimental to the catalytic performance.To tackle this hurdle,we successfully prepared a functional and stable porphyrinic metal-organic framework(MOF),PCN-224-RT,as a host for encapsulating metal nanoparticles by direct stirring at room temperature.As a result,Pt@PCN-224-RT composites with well-dispersed Pt NPs can be constructed by introducing pre-synthesized Pt NPs into the precursor solution of PCN-224-RT.Of note,the rapid and simple stirring method in this work is more in line with the requirements of environmental friendly and industrialization compared with traditional solvothermal methods.

Room-temperature synthesis of layered open framework cathode for sodium-ion batteries

The synthesis of active electrode materials at room temperature is one of the effective strategies to reduce the fabrication cost of sodium ion batteries(SIBs).Herein,a layered material(Na_(2)[(VO)_(2)(HPO_(4))_(2)C_(2)O_(4)]·2H_(2)O,abbreviated as NVPC followingly)with open-framework structures has been successfully prepared at room temperature under ambient conditions and is evaluated as a cathode for SIBs.It is revealed that NVPC cathode can deliver a maximum reversible capacity of ca.70 mAh/g at 10 mA/g,and exhibit superior rate capability and cycling performance:at 50 mA/g,maximum reversible capacity ca.50 m Ah/g with capacity retention of 88.4%over 250 cycles corresponds to only 0.046%capacity decay per cycle;at 100 mA/g,a maximum reversible capacity of 35 mAh/g with capacity retention of60.9%over 500 cycles.This study demonstrates a practical example of a low-cost synthesis of the cathode materials for SIBs.At the same time,the systematic electrochemical research results also show promising prospects for long lifespan low-cost SIBs.

A review on room-temperature self-healing polyurethane:synthesis,self-healing mechanism and application

Polyurethanes have been widely used in many fields due to their remarkable features such as excellent mechanical strength, good abrasion resistance, toughness, low temperature flexibility, etc. In recent years, room-temperature self-healing polyurethanes have been attracting broad and growing interest because under mild conditions, room- temperature self-healing polyurethanes can repair damages, thereby extending their lifetimes and reducing maintenance costs. In this paper, the recent advances of room-temperature self-healing polyurethanes based on dynamic covalent bonds, noncovalent bonds and combined dual or triple dynamic bonds are reviewed, focusing on their synthesis methods and self-healing mechanisms, and their mechanical properties, healing efficiency and healing time are also described in detial. In addition, the latest applications of room-temperature self-healing polyurethanes in the fields of leather coatings, photoluminescence materials, flexible electronics and biomaterials are summarized. Finally, the current challenges and future development directions of the room-temprature self-healing polyurethanes are highlighted. Overall, this review is expected to provide a valuable reference for the prosperous development of room- temperature self-healing polyurethanes.

碳六型聚羧酸减水剂的制备与性能研究

目的确定碳六型聚羧酸减水剂的最佳制备工艺,解决碳六型聚羧酸减水剂随存放时间延长保塑性下降的问题。方法以丙烯酸(AA)、乙二醇单乙烯基聚乙二醇醚(EPEG)及次亚磷酸钠(SHP)等为主要原材料,通过自由基共聚反应,制备得到了碳六型聚羧酸减水剂。通过水化热、SEM、XRD等测试方法,研究碳六型聚羧酸减水剂的性能。结果当聚醚单体分子量为3000、酸醚摩尔比为5∶1、起始反应温度为15~20℃时,碳六型聚羧酸减水剂的分散性及保塑性最佳。结论碳六型聚羧酸减水剂在分散性及保塑性方面均优于甲基烯丙基聚氧乙烯醚(HPEG)型减水剂;加入稳定剂后,碳六型聚羧酸减水剂的保塑性得到了明显提升。

2-Methylimidazole assisted ultrafast synthesis of carboxylate-based metal–organic framework nano-structures in aqueous medium at room temperature

Carboxylate-based metal–organic frameworks(CMOFs)have received considerable attentions for their high stability,catalytic activity,and porosity.However,synthesis of CMOFs requires high temperature,pressure,and long reaction time.Here,we explored the activity of 2-methylimidazole(2-MIM)for ultrafast synthesis of CMOF nanostructures(CMOFNs),in aqueous medium at room temperature and reaction time of 10 min.Seven CMOFNs have been synthesized by using Al3+,Cr3+,Cu2+,Fe3+,In3+,or Cd2+salt and1,4-bezenedicarboxylic acid,or 1,3,5-benzenetricarboxylic acid.Through this technique,the CMOFs with space time yield 181–501 kgcrystal sizes of ca.200–700 nm was obtained.

Green synthesis of NiFe LDH/Ni foam at room temperature for highly efficient electrocatalytic oxygen evolution reaction

Clean energy technologies such as water splitting and fuel cells have been intensively pursued in the last decade for their free pollution. However, there is plenty of fossil energy consumed in the preparation of the catalysts,which results in a heavy pollution. Therefore, it is much desired but challenging to fabricate high-efficiency catalysts without extra energy input. Herein, we used a facile one-pot room-temperature method to synthesize a highly efficient electrocatalyst of nickel iron layered double hydroxide grown on Ni foam(NiFe LDH/NF) for oxygen evolution reaction(OER). The formation of the NiFe LDH follows a dissolutionprecipitation process, in which the acid conditions by hydrolysis of Fe^3+ combined with NO3^- could etch the NF to form Ni^2+. Then, the obtained Ni^2+ was co-precipitated with the hydrolysed Fe^3+ to in situ generate NiFe LDH on the NF. The NiFe LDH/NF exhibits excellent OER performance with a low potential of about 1.411 V vs. reversible hydrogen electrode(RHE) at a current density of 10 m A cm^-2, a small Tafel slope of 42.3 mV dec^-1 and a significantly low potential of ~1.452 V vs. RHE at 100 mA cm^-2 in 1 mol L^-1 KOH. Moreover, the material also keeps its original morphology and structure over 20 h. This energy-efficient strategy to synthesize NiFe LDH is highly promising for widespread application in OER catalyst industry.

采用逆合成分析与纯有机催化室温合成4-溴查尔酮的实验设计

以4-溴查尔酮为目标分子,通过逆合成分析法,从6条路线中分析出含有5项诺贝尔奖成果的合成途径,通过对比,最后选择出2021年诺奖成果“纯有机催化”室温合成4-溴查尔酮。以新试剂L-脯氨酸为催化剂,室温下通过对溴苯甲醛和苯乙酮的羟醛缩合反应合成4-溴查尔酮,并进行一系列正交实验,优化反应条件。该反应具有原料价格低廉、反应条件温和等优点。通过简单的反应,将多项诺奖成果与纯有机催化引入实验教学中,避免“照方抓药”式教学,紧贴科学前沿,深化有机合成学习,有利于培养学生创新意识。

一锅法合成可印刷室温磷光二氟化硼衍生物

纯有机室温磷光(RTP)材料因其潜在的应用价值而备受关注.迄今,多数已报道的有机RTP材料在晶态下发射出较强的RTP,但在溶液加工过程中易生成无定形态,从而失去RTP性能.本文通过一锅法两步反应,合成了含有多个甲氧基的二氟化硼衍生物(BF2-tPMO).晶体结构分析表明,多个甲氧基的存在构建了有效的分子间非共价相互作用.这些非共价键作用可抑制分子运动,保持较高的发光效率.此外,这些非共价键作用能够使其在溶剂处理后依然保持晶态性质,进而保持RTP性能.实验结果表明,BF2-tPMO可溶解在不同溶剂中且在溶剂蒸发后仍能保持相同的RTP特性,为易加工型RTP材料的设计提供了有效的策略.

亚胺类共价有机框架材料涂层搅拌棒对雌二醇吸附性能的研究

为研究亚胺类共价有机框架(covalent organic framework,COF)的微观结构、表面性质及其对雌二醇的吸附特性,以1,3,5-三(4-氨苯基)苯(1,3,5-tris(4-aminophenyl)benzene,TAPB)和1,3,5-苯三甲醛(1,3,5-benzotrialdehyde,BTC)为单体,在室温条件下合成了亚胺类共价有机框架材料TAPB-BTC-COF,优化合成中催化剂冰醋酸的用量。用傅里叶红外光谱(Fourier transform infrared spectroscopy,FT-IR)、X射线衍射(X-ray powder diffraction,XRD)、扫描电子显微镜(scanning electron microscope,SEM)、热重分析(thermogravimetric analysis,TGA)、N 2等温吸附-脱附曲线等手段对合成的TABP-BTC-COF材料进行了表征,并采用物理涂覆法制备TABP-BTC-COF涂层搅拌棒。结果表明,催化剂的用量会影响COF的晶型;TABP-BTC-COF涂层搅拌棒的吸附动力学过程符合准二级吸附动力学(R 2=0.9714),属于化学吸附。该研究为TAPB-BTC-COF涂层搅拌棒对环境中雌二醇的检测应用提供了一定的理论依据。

A New Route for the Rapid Synthesis of Metal–Organic Frameworks at Room Temperature

Rapid synthesis of metal–organic frameworks(MOFs),especially high-valence MOFs at roomtemperature without external energy,is a challenging topic.In this work,a stable radical solution has been discovered.Various MOFs with versatile metal nodes and ligands were rapidly synthesized at room temperature in the absence of external energy.Especially,MOFs with conjugated ligands achieved instantaneous architecture(in less than 1 s)and quantitative yield.Radicals in the solution play a crucial role in the accelerated kinetics,and the new radical route paves a cyclic pathway for the MOF synthesis.The mechanism has been thoroughly investigated by electron paramagnetic resonance,in situ proton nuclear magnetic resonance,X-ray absorption spectra,in situ small-angle X-ray scattering-wide-angle X-ray scattering,and density functional theory calculations.

新型室温离子液体六烷基胍盐的制备及性质

The synthesis and properties of a novel room-temperature ionic liquid hexaalkylguanidium salts 4 and 5 were reported. The reaction of 1,3-dimethyl-2-imidazolidinon with POCl 3 and n-BuNH 2 afforded to pentaalkyl-guanidine(2), which reacted with CH 3I, generated hexaalkylguanidium(3). The hexaalkylguanidium salts 4 and 5 were synthesized by the reaction of hexaalkylguanidium(3) with KPF 6, AgBF 4 respectively. The results showed that both compounds 4 and 5 were room-temperature ionic liquids. The structures of these compounds were determined by 1H NMR, 13C NMR, IR and MS spectra data. Compounds 4 and 5 were found to have better solublities in organic solvents and better thermal stabilities.